html {
  box-sizing: border-box;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: url("http://wes.io/hx9M/oh-la-la.jpg") center no-repeat;
  background-size: cover;
}
